I've been getting a KS and EGR code for the last two weeks. I've checked it a couple of times and always the same. I'm planning on pulling the EGR and cleaning it. Why wouldn't you get one code at a time?

 

if you had one problem, youde get one code. apparently you have 2 problems, so youre getting 2 codes.

 

That's what you would think but I won't get a code for 30/100 miles and then I pull over and check just after the cel comes on and two codes every time.

 

Maybe they are related? I don't know for sure..anybody know?

 

so before i try to tell you why this is happening, let me make sure i understand what exactly is happening:

the light comes on, you reset it and clear the codes, drive 30-100miles and the light and codes come back? correct?

 

More then likely the KS isnt bad. It is being triggered by the EGR by fixing the EGR the KS will more then likely go off too. If it comes back after the EGR is fixed then the KS needs replaced to.

 

wizzard00 yes, that's it. Mx, your thinking th KS is one of the infamous "ghost codes"?

 

it might just be the knock sensor...i had two codes thrown(knock sensor and my o2 sensor bank 2 sensor 1) replaced all o2 sensors just in case and still got the codes...turns out it was the knock sensor the entire time...id check that out. only problem is that those things are not cheap

 

Some misinformation here.

where are you getting this from? Based on what? A Knock sensor code does not mean the car is sensing "knock" or preignition. a Knock Sensor code means there is something wrong with the communication between the KS and the computer. So although a faulty EGR may increase the amount of preignition............it will not cause a knock sensor code. If you fix the EGR problem and reset the light the KS code will still be there. You just wont know it because it wont set the light off.



A "ghost code" is still a code. It is simply a code that will not set off the light. It does not mean there is no problem there. Why does the light come back on? Because you havent fixed anything. You can't confuse the car into thinking everything is ok.


So in closing, fix the EGR problem and change the knock sensor.

 

exactly what i was going to say. and thanks for being a wise *** with the 'wizzard00'...next time when you post something this rediculously idiotic, i wont bother help you.

 

Most vq30's get knock sensor codes (mine has one) and they rarely set the MIL. Nine times out of ten it's corrosion in the connector between the sensor and the harness. Try cleaning the terminals on both, then consider buying a sensor if that doesn't fix it.

 

From what I understand from my mechanic (works for me) is to fix the code that comes first on the scanner. Then clear the codes and see what comes back. I had the exact same thing as you, knock sensor and EGR. The knock sensor was first. We cleared them both and about a week later they were both back. I replaced the knock sensor. Cleared the codes again and now neither has come back. It's been three weeks and about 700 miles of driving.

My guess is the retarded timing caused by the knock sensor made my car run rich and temporarily foul the EGR.

 

hmm im not sure why the egr would be set off by the KS but your theory to me doesnt make sense. EGR is responsible for recirculating the NOx gas back into the intake manifold to re-burn it/help the cat break it down and ultimatly produce less NOx out the tailpipe. therefore, if it were running rich and producing more NOx it would make more sense to get a cat code because the rear O2 would be sensing more NOx in the exhaust.

edit: on second thought...i guess it could possibly produce an egr code since ultimatly, it is the egr's resposiblity to recirculate the NOx...it would depend what the exact code was i guess. if it were something like "egr flow insufficiant" than i can see why it would throw an egr code while running rich but if it were something like 'egr stuck open/closed' than it wouldnt make sense that the code was due to running rich.